. Author manuscript; available in PMC: 2015 Oct 1.

Published in final edited form as: Obstet Gynecol. 2014 Oct;124(4):662–669. doi: 10.1097/AOG.0000000000000478

Table 2.

Effect of weight change since age 18 on relative risk (RR) of fetal loss stratified by BMI at age 18.

	Full Population 25,539 pregnancies 16,903 women RR (95% CI)	BMI at Age 18		P for Interaction
	Full Population 25,539 pregnancies 16,903 women RR (95% CI)	BMI < 25 kg/m² 23,398 pregnancies 15,484 women RR (95% CI)	BMI ≥ 25 kg/m² 2,141 pregnancies 1,419 women RR (95% CI)	P for Interaction
RR for 5 kg change in body weight from age 18
Model 1: Fully adjusted^*	1.03 (1.02, 1.04)	1.03 (1.01, 1.04)	1.04 (1.02, 1.07)	0.36
Model 2: Fully adjusted + BMI at age 18	1.03 (1.02, 1.04)	1.03 (1.01, 1. 04)	1.04 (1.02, 1.07)	0.54
Model 3: Fully adjusted + BMI at age 18 + indicator for prepregnancy overweight/obesity	1.02 (1.01, 1.04)	1.02 (0. 99, 1.04)	1.03 (1.00, 1.07)	0.49

Abbreviations: BMI, body mass index; RR, relative risk.

Adjusted for age (continuous), smoking status (never, former, current, missing), physical activity (< 3 MET-h/wk, 3–8.9 MET-h/wk, 9–17.9 MET-h/wk, 18–26.9 MET-h/wk, 27–41.9 MET-h/wk, >42 MET-h/wk, and missing), year of pregnancy (continuous), history of infertility (no, yes, and missing), current multivitamin use (no, yes, missing), marital status (married, not married), race (white, other).